Ekrn.exe (669) Craps Out

Well, about two weeks ago I think, I had updated to 669 on a handful of systems. Since then, IE and Firefox intermittantly cause ekrn.exe to fail on a couple of those systems. I get a memory access error where "0x71a6b2fa" accessed "0x00000008", the process (I think) fails and restarts, and I have to wait for all that to calm down to resume browsing. Whatever caused the fail also causes the page/tab to halt and I have to refresh it. Sometimes, it's in the middle of something that should not be interrupted, and creates havoc with some database somewhere.